diff --git a/src/ArcCollection.ts b/src/ArcCollection.ts
index 846f9d3..9c6ce6e 100644
--- a/src/ArcCollection.ts
+++ b/src/ArcCollection.ts
@@ -13,7 +13,6 @@ import {
   error,
   initializeArray,
   intersectSegments,
-  utilsForEach,
 } from "./utils";
 
 export type ArcCollection = {
@@ -255,13 +254,16 @@ export function ArcCollection$findSegmentIntersections(self: ArcCollection) {
     self,
     stripeSizes.reduce((acc, cur) => acc + cur, 0),
   );
-  let offs = 0;
-  const stripes: any[] = [];
-  utilsForEach(stripeSizes, (stripeSize: number) => {
-    const start = offs;
-    offs += stripeSize;
-    stripes.push(stripeData.subarray(start, offs));
-  });
+  let offset = 0;
+
+  const stripes: Uint32Array[] = [];
+  for (let i = 0; i < stripeSizes.length; i++) {
+    const stripeSize = stripeSizes[i];
+    const start = offset;
+    offset += stripeSize;
+    stripes.push(stripeData.subarray(start, offset));
+  }
+
   // Assign segment ids to each stripe
   initializeArray(stripeSizes, 0);
   ArcCollection$forEachSegment(
diff --git a/src/utils.ts b/src/utils.ts
index e93f980..511383c 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,35 +1,8 @@
-// @kobakazu0429----utils.ts
 export function error(...args: any[]) {
   const msg = args.join(" ");
   throw new Error(msg);
 }
 
-export function isArrayLike(obj: any) {
-  if (!obj) return false;
-  if (isArray(obj)) return true;
-  if (isString(obj)) return false;
-  if (obj.length === 0) return true;
-  return obj.length > 0;
-}
-
-function isString(obj: any) {
-  return obj != null && obj.toString === String.prototype.toString;
-}
-
-function isArray(obj: any) {
-  return Array.isArray(obj);
-}
-
-// Support for iterating over array-like objects, like typed arrays
-export function utilsForEach(arr: any, func: any, ctx?: any) {
-  if (!isArrayLike(arr)) {
-    throw new Error(`#forEach() takes an array-like argument. ${arr}`);
-  }
-  for (let i = 0, n = arr.length; i < n; i++) {
-    func.call(ctx, arr[i], i);
-  }
-}
-
 export function initializeArray(arr: any, init: any) {
   for (let i = 0, len = arr.length; i < len; i++) {
     arr[i] = init;